Each year 18 out of 100,000 Germans come down with gastric carcinoma. In Japan, 126 out of 100 000 people are affected. This means about 156,000 incidences per year in Japan alone. Similarly, gastric carcinoma is one of the most frequent causes of death in China, Taiwan and Korea. Until present, the most promising therapeutic method for treating such carcinomas has been the application of cytostatica within a chemotherapeutic regimen. However, this approach suffers from significant side effects.
In contrast, radioimmunotherapy approaches use protein structures located on the membrane of tumor cell lines to bind cytotoxic active substances via a carrier. In most cases, overexpression of the binding molecule at the tumor cell is an important variable in this treatment method. Given that the target molecule for the tumor associated antibodies can also be expressed is to a lower extent on the surface of non-tumor cells in the organism, such therapeutic agents can also bind to also binds to non-tumor cells. There is a need to develop improved methods for the purification of radium for use in radioimmunotherapeutic methods. This invention addresses this need.